The invention concerns a device for the separation of solid particles from a gas flow that is loaded with solid particles. In particular for the removal and separation of coarsely grained solid particles, with a housing through which the gas flow has to pass and which is provided with a discharge opening for solid particles and in which a generally dynamically balanced guidance and torsion element is arranged within a distance to the inner wall of the housing and which is also provided with a submerged tube at the discharge opening.
Gas flows that are loaded with solid particles frequently occur in various situations, particularly in the technology of mechanical processing, in which the size of the solid particles can include an extensive range of grain sizes. Gas flows of this sort cannot be discharged into the environment without first being cleaned for ecological reasons. Additionally, at least a substantial part of the solid particles (specifically, those that are coarsely grained) can be reused as a raw material, if they could be separated and removed from the gas flow.
Particularly in areas of heat technology, a frequent problem is that subsequently arranged components of the facility such as furnace chambers, heat exchangers, filters and similar devices, should be protected from sludge (so-called fouling). Furthermore, the effectiveness of the resulting heat transfer steadily decreases. One application of this sort is the port-end of a cupola.
Another technologically similar example is the exhaust flow from processing plants in foundries or for foundry dust removal facilities. In these situations the exhaust gas flow contains a finely grained portion having a particle size of less than 90 microns as well as a considerable portion of coarsely grained particles having particle sizes greater than 100 microns. These particles can be reused in an economically advantageous manner by removing them from the exhaust gas flow and separating the finely grained portion, thus simultaneously reducing the quantity of solid particles that must be deposited in waste sites.
It is known that the dust created in blast furnaces, cupolas and steel processing facilities contain harmful materials, such as alkalis, Zn and Pb, particularly in the finely grained portion (e.g., those particles having a grain size from 0 to approximately 70 microns), while the coarsely grained portion having larger particle sizes contains less harmful materials and is considerably easier to process and reuse after it is separated from the finely grained portion.
So-called cyclones are known for separating solid particles from gas flows, which essentially include a generally dynamically balanced container with a vertical axis of symmetry into which the gas flow to be cleaned is introduced in a generally tangential manner so that the gas flow rotates about the vertical longitudinal or symmetry axis. The gas flows upward with a more or less helical-shape around the rotation axis in the cyclone. Separation of the solid particles results from the deceleration caused by the surface friction of the wall. The particles are discharged from the lower end section of the cyclone through a solid particle discharge opening, while the cleaned gas flow is discharged from the cyclone through a gas discharge opening on the top. Such cyclones not only require considerable space, particularly with respect to their height requirements, but are also relatively demanding. Furthermore, they are usually not able to separate certain grain fractions, which can be very advantageous in many cases for the reasons indicated above.
Another known separation device is a so-called spark separator, which in construction corresponds to the present invention, but such a separator does not at all fulfill the demands placed upon it. In particular, the known spark separators do not have an adjustable rotation speed nor can they vary the particle size to be separated.
The known separation elements work within relatively rigid limitations with respect to their operational parameters, and hence a change in the gas quantity and/or the gas temperature, as well as the dust content of the gas, can lead to different separation efficiencies and change the separation efficiency curve with regard to its steepness and average particle size.
For certain technological applications, for example when the separator is placed behind the port-end of a cupola, it is advantageous if the separation efficiency does not considerably vary upon changes of the operational parameters.
The problem with the prior art is that there is no separator of the type described above for separating certain grain fractions, particularly coarsely grained fractions, from a gas flow loaded with harmful materials in order to process and further use these materials, which is well-suited to be used under different pressure and temperature conditions, as well as with different gas amounts and different loads of solid particles in the gas while causing the least possible pressure loss and which can be produced in an economical manner and subsequently installed in already existing facilities and, particularly in relation to the cyclones, have a relatively low structural height.